Preheat the oven to 425°F. Line a baking sheet with parchment paper. Toss potatoes with olive oil, salt, and pepper. Place in a single layer on a parchment-lined baking sheet. Roast in the oven for 45-50 minutes, flipping halfway thru until potatoes are golden and crispy.
Meanwhile, add a bit of olive oil and the diced pancetta in a hot skillet. Cook, stirring frequently until pancetta is crispy and cooked through, about 5 minutes. Remove from the skillet and set aside.
In the same skillet, without draining the pan, add butter to the skillet, followed by shallots, and garlic with lots of salt and pepper. Cook over medium heat, stirring every minute or so until the shallots are translucent about 5 minutes. Then, add in the herbs and stir constantly for 30 seconds or so. Remove the skillet from the heat.
Add tuna to the food processor, followed by the lemon zest, lemon juice, Worcestershire sauce, balsamic vinegar, ricotta cheese, parmesan, a drizzle of honey, the cooked herbs, shallots, garlic, and most of the cooked pancetta, reserving some for garnishing later. Food process and add remaining olive oil in a thin stream until smooth, adjust salt and pepper to taste.
Spread tuna mousse over top of the crispy potato slices. Garnish with a drizzle of olive oil, salt, pepper, parmesan cheese, more herbs, and crispy pancetta.
Store leftovers in an airtight container for 2-3 days. Do not freeze.